Hand Pathology Flashcards
What two structures form the carpal tunnel?
Carpal bones
Flexor retinaculum
What passes through the carpal tunnel?
Median nerve
Nine flexor tendons - 4FDP, 4FDS, 1FPL
What does the median nerve innervate?
Lumbricals 1 and 2
Opponens pollici
Abductor pollicis brevis
Flexor pollicis brevis
Name the causes of carpal tunnel syndrome
Pregnancy Rheumatoid arthritis Diabetes Chronic renal failure Hypothyroidism Idiopathic Wrist fracture
How will carpal tunnel syndrome present?
Parathesiae - thumb and radial 2 fingers
Worse at night
Loss of sensation
Weakness and clumsiness
Describe the examination in suspected carpal tunnel
Tinel’s test positive - percuss over nerve
Phalen’s test - hyper-flex wrists (prayer)
Thenar atrophy
What is the treatment for carpal tunnel?
Wrist splints
Steroid injection
Decompression under local anaesthetic
What happens in Dupuytren’s Contractures?
Specialised palmar fascia undergoes hyperplasia forming nodes and contractors at MCP and PIP joints
Describe the pathology of dupuytren’s
Proliferation of myofibroblast cells and abnormal collagen production (3 instead of 1), skin may be adherent to the fascia and puckered with palpable nodes present
What fingers care commonly affected by dupuytren’s?
Little finger and ring finger
What diseases can cause Dupuytren’s?
Familial Alcoholic cirrhosis Diabetes Thyroid Epilepsy medication
Name two disease associated with Dupuytren’s
Peyronies - penis
Leddrhose - feet
Name three types of surgery that can be done on dupuytren’s
- fasciectomy (removal of tissue)
- fasciotomy (division of cords)
- amputation
What is a ganglion cyst?
Mucinous filled cyst found adjacent to a tendon/synovial joint
What are the names for ganglionic cyst depending on location?
DIP - mucous cyst
Wrist - dorsal/volar
Knee - bakers cyst
Describe the presentation of a ganglion cyst
Localised irritation/pain, firm smooth rubbery and should transluminate
What deformity will radial nerve palsy cause?
Wrist drop - extensor muscles don’t contract
What will median nerve lesion cause?
Distal - Ape hand
Proximal - hand of benediction
What nerve damage will cause abnormal `OK’ sign?
Anterior interosseous
How will ulnar nerve damage present?
Ulnar claw - paralysis of 3rd and 4th lumbrical
Describe ulnar paradox
Ulnar nerve damage can denervate flexor digitorum profundis - weakens the flexion of IP joints in 4th and 5th joint
How does trigger finger arise?
Tendonitis of flexor tendon to a digit can result in nodular (scarring and fibrosis) enlargement.
Where does trigger finger usually occur?
Distal to fascial pulley over MC neck - the nodule catches on and may get stuck - A1 pulley
Middle and ring finger
How is trigger finger treated?
Steroid injection around the tendon
Surgery - incision of the pulley to allow the tendon to move freely - only A1 pulley
Name the condition which involves swelling of the sheet of the 1st dorsal compartment tendons
DeQuervain’s Tenosynovitis
Which tendons are affected by DeQuervain’s Tenosynovitis?
Abductor pollicis longus
Extensor pollicis brevis
How does DeQuervain’s Tenosynovitis present?
Spontaneous red/swollen area proximal to the thumb
Name two tests for DeQuervain’s Tenosynovitis
Finkelstein
Eichhoff’s
How is DeQuervain’s Tenosynovitis treated?
NSAIDs, splint, rest, steroids, decompression
What investigation should be done in DeQuervain’s Tenosynovitis?
Xray
What is paronychia?
Infection within the nail fold - children or people who bite their nails
How is paronychia managed?
Elevate, antibiotics, incise and drain
What is a surgical emergency in the hand?
Flexor Tendon Sheath Infection
Describe flexor tendon sheath infection
Infection of sheath tracking up palm and arm - limited extension due to pain
What are Kanavel’s cardinal signs?
Affected finger held in fixed flexion
Fusiform swelling over finger
Painful to percuss over sheath
Painful on passive extension
Describe the 5 types of fingertip injury
1 - soft tissue 2 - soft tissue and nail 3- soft tissue, nail and bone 4 - proximal 1/3 phalanx 5 - proximal to DIP
How are the 5 types treated?
1 and 2 - dressing
3 - repair bed and stabilise
4 - ablation
5 - V-Y flap
How can subungal haematoma be treated?
Pressure causes pain - burning a paper clip with a bunsen to relieve pressure and pain
What are the two types of surgery for hand fractures?
Closed reduction using K wires
Open reduction using plates
What is skiers/gatekeepers thumb?
Ulnar collateral ligament injury due to a fall on an outstretched hand
How is skiers thumb treated?
Splint
Surgical repair of ligament
Describe boxer’s fracture and the treatment
Minimal displacement, no rotation
Buddy strap and early mobilisation of 5th MC near knuckle
What is Mallet finger?
Soft tissue injury or avulsion fracture results in injury to the tendon - straightens the end of the finger
Tender/bruising resisted extension
What is the treatment for mallet finger?
Splint 24/7 for 6 weeks
Surgery in chronic cases
What is Bennett’s Fracture?
Fracture at base of first metacarpal bone with subluxation or dislocation
- pain swelling weakness in pinch grasp
How is Bennett’s fracture managed?
Cast and rest
Closed reduction
What is eschar?
Thick, leathery inelastic skin which can form after burns - requires surgical release to allow movement
